desinfection

Question 1

The Basic Steps to be folloewd in cleaning (didnt mark as important, put is printed bold)

Answer 1

• All manure and bedding materials should be taken away and disposed of in an
appropriate manner (incinerated, buried or ploughed into the earth)
• Earth and sand flooring must be scraped down to the uncontaminated soil, all
contaminated soil should be removed and subsequently sterilized, buried or ploughed
under
• Any material - such as wooden planks and boards - which cannot be thoroughly
sanitized must be removed and incinerated or buried
• All interior surfaces (e.g. ceilings, floors and walls) must be thoroughly cleaned with a
powerful detergent
• All machinery and tools used in the removal of soiling (e.g. manure loaders, shovels,
brushes and scrapers) must be thoroughly sanitized.
• The selection of detergents is important. A product which could interfere with or
neutralize the chemical action of the disinfection agent should not be used.

Question 2

List what are the major causes of desinfection failure!

Answer 2

1) Over-dilution of disinfectant during pre-mixing or application (hypochlorite
needs 3%/4%, commercial is 9%)
o 2) Incomplete or inadequate cleaning
o 3) Poor disinfectant penetration or coverage
o 4) Insufficient contact time on surfaces
o 5) Inadequate temperature and humidity while the material is being applied

• Failure can also result from inactivation or neutralization of the disinfectant, due to
the presence of residual cleaning liquids which were not adequately flushed away
before the disinfectant was applied.
• A common mistake is to select a product which is ineffective against the contaminating
organisms.
• The entire process must be repeated if examination of sentinel animals or
laboratory tests on environmental samples indicate that pathogens have
survived the procedure

Question 3

chlorine desinfectant - what is the field of application?

Answer 3

are very effective in the absence of organic material (only effective if NO organic material)
o Other factors affecting the efficacy of chlorine-based disinfectants are concentration, pH, presence of natural proteins and presence of ammonia (urine should be cleaned before use!)

Chlorine has bleaching and germicidal properties and is commonly used in disinfection, sanitizing and water purification. In high concentrations, chlorine is used for sewage treatment. Chlorine disinfectants and sanitizers are readily available, inexpensive, have a broad antimicrobial spectrum (vir, fungi, bacteria) and present minimal environmental hazards

• Hypochlorites are still commonly used in animal health programes. Hypochlorites have broad spectrums of antibacterial and antiviral action. These substances are corrosive, easily neutralized by organic material and decompose readily if stored for longer.
• Chlorinated lime — a hygroscopic white powder containing a variety of calcium and chlorine compounds — is frequently sprinkled and made wet in barnyards and on piles of manure, the released chlorine serving as a general disinfectant.

Question 4

Iodine Based desinfectants

Answer 4

• Widely used in vet also
• Many forms of iodine find common use in animal health and food processing
disinfection. Aqueous iodine (Lugol’s solution) or alcoholic iodine solutions (tinctures of
iodine) are commonly used as antiseptics.
• Iodophores are disinfectants formed by combinations of iodine with various carrier
compounds. This releases iodine in an acid medium and have disinfectant properties
which affect bacteria, viruses and some spores. Iodophores are used for general
disinfection and cleaning bovine teat dips, and surgical scrubs.
• Hard water and the presence of large amounts of organic material reduce the activity of
iodophores, but these disinfectants can function effectively in the presence of traces of
organic material (clean and rinse to be more effective) Also expensive!

Question 5

How to choose a desinfectant?

Answer 5

• Suitable for typical food factory applications;
• Non-toxic in the product;
• Safe for cleaning operatives;
• Non-tainting; Effective.

Question 6

Desinfection?

Answer 6

means the operation, after thorough cleansing, destined to destroy the
infectious agents of animal diseases, including zoonoses this applies to animals, premises,
vehicles and different objects which can be directly or indirectly contaminated by animals
or animal products. Before applying disinfectant, thorough cleaning must be performed.
(not same as sterilising

Question 7

Sterilizing agents?

Answer 7

are used to produce total destruction of microorganisms under
controlled industrial, laboratory or hospital conditions. Heat, chemicals and irradiation
are the most commonly-used sterilizing agents

Question 8

Sanitizers?

Answer 8

combine cleaning and disinfection functions on surfaces which are
relatively free of gross contamination. They are used to reduce bacteria to safe levels
on food- or water-handling equipment without causing adulteration of the product

Question 9

Antiseptics?

Answer 9

inhibit the growth of microorganisms on living tissue. They are used in
wound treatment and in preparing the skin for surgery. Antiseptics are usually the
weakest and least toxic of the surface antimicrobials

Question 10

What should be considered when using desinfectants?

Answer 10

The following should be considered:
o Few universal disinfectants exist;
o Whereas hypochlorite, which is very often used, may be regarded as a universal
Sunna State Vet
disinfectant, its effectiveness is diminished by prolonged storage and it is
therefore necessary to check its activity before use. A concentration of 0.5%
active chlorine appears necessary for satisfactory disinfection